Pore-scale investigation of forced imbibition in porous rocks through interface curvature and pore topology analysis  

作　　者：Jianchao Cai Xiangjie Qin Han Wang Yuxuan Xia Shuangmei Zou 

机构地区：[1]State Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum,Beijing,102249,China [2]Hubei Key Laboratory of Oil and Gas Exploration and Development Theory and Technology,China University of Geosciences,Wuhan,430074,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2025年第1期245-257,共13页岩石力学与岩土工程学报(英文)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42172159 and 42302143);the Postdoctora Fellowship Program of the China Postdoctoral Science Foundation(CPSF)(Grant No.GZB20230864).

摘　　要：Forced imbibition,the invasion of a wetting fluid into porous rocks,plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide.However,the interface dynamics influenced by complex topology commonly leads to non-wetting fluid trapping.Particularly,the underlying mechanisms under viscously unfavorable conditions remain unclear.This study employs a direct numerical simulation method to simulate forced imbibition through the reconstructed digital rocks of sandstone.The interface dynamics and fluid–fluid interactions are investigated through transient simulations,while the pore topology metrics are introduced to analyze the impact on steady-state residual fluid distribution obtained by a pseudo-transient scheme.The results show that the cooperative pore-filling process promoted by corner flow is dominant at low capillary numbers.This leads to unstable inlet pressure,mass flow,and interface curvature,which correspond to complicated interface dynamics and higher residual fluid saturation.During forced imbibition,the interface curvature gradually increases,with the pore-filling mechanisms involving the cooperation of main terminal meniscus movement and arc menisci filling.Complex topology with small diameter pores may result in the destabilization of interface curvature.The residual fluid saturation is negatively correlated with porosity and pore throat size,and positively correlated with tortuosity and aspect ratio.A large mean coordination number characterizing global connectivity promotes imbibition.However,high connectivity characterized by the standardized Euler number corresponding to small pores is associated with a high probability of non-wetting fluid trapping.

关 键 词：Forced imbibition Porous rocks Interface dynamics Pore topology Residual fluid distribution 

分 类 号：TU452[建筑科学—岩土工程]